abstract With the use of 2 monoclonal antibodies (MAbs) against excretory/secretory (ES) antigens of adult Angiostrongylus cantonensis , a new method was developed for double antibody sandwich ELISA for the detection of circulating antigens (CAg). To evaluate the sensitivity of the new procedure, the CAg in sera of rats (80) and mice (15) infected with A. cantonensis , as well as CAg in sera of clinically confirmed angiostrongyliasis patients (70), were evaluated. Cross-reaction testing was used to determine the specificity of serum from patients infected with Ascaris lumbricoides , Trichinella spiralis , Toxoplasma gondii , Schistosoma japonicum , Paragonimus westermani , Clonorchis sinensis , Echinococcus granulosus , Spirometra , and Taenia solium , as well as normal healthy people. The results proved that the sensitivity and the specificity of the new method were totally effective for the detection of A. cantonensis CAg. The assay is highly sensitive, specific, and reproducible, with easy handling and excellent cost effectiveness, and thereby provides a new method for the accurate diagnosis of angiostrongyliasis.
A seroepidemiological survey was carried out in China during 2009–2010 to determine the extent of circulating antigens (CAg) for Angiostrongylus cantonensis in the Chinese population using the gold immunochromatographic assay, with the objective of elucidating the nationwide prevalence of angiostrongyliasis in China. A total of 1,730 blood samples was collected and assayed from the general adult population (the “general group”), and those involved in aquaculture or processing of snails Achatina fulica and Pomacea canaliculat (the “occupational group”) from 5 provinces (Fujian, Hunan, Guangdong, Guangxi, and Zhejiang) and 1 municipal city (Beijing). The overall seroprevalence for the “occupational group” was 7.4% (40/540), which was significantly higher ( P < 0.001) than that of the “general group” (0.8%, 9/1,190). The seroprevalence in males (9.5%) was significantly higher than in females (4.2%) ( P < 0.05). These results demonstrate that angiostrongyliasis represents a significant zoonotic disease in China, requiring the strengthening of food safety for control of this food-borne disease.
Little is known of the seroprevalence of Toxoplasma gondii in bred cynomolgus monkeys ( Macaca fascicularis ) in China. In the present survey, 240 serum samples of cynomolgus monkeys from 4 nonhuman primate centers in Guangxi Zhuang Nationality Autonomous Region (GX), and 120 serum samples from 2 nonhuman primate centers in Guangdong Province (GD) were obtained, and the modified agglutination test (MAT) was performed to assay for anti– T. gondii antibodies. Antibodies to T. gondii (MAT titer of 1∶16 or higher) were found in 0 of 120 (0/120) samples in GD, and 5 (2.1%) of 240 sera with titers of 1∶16 in 1, 1∶64 or higher in 4 in primate centers from GX. The total prevalence of T. gondii in bred cynomolgus monkeys was 1.4% (5/360, MAT titer ≥ 1∶16) in southern China according to our investigation. To our knowledge, this is the first seropositive report in China on the prevalence of anti– T. gondii antibodies in bred cynomolgus monkeys using MAT.